Now, using that photo I supplied of the Chicago skyline, compute the angle above that horizon for a building that is 1400 feet tall from the point where the photo was taken and let's compart your figures with what is depicted in the photo, and then, we can work from there.
We've already done all this in previous calculations. Did you skip through those?
At any rate, at 50 miles 1,652.3ft will be below the Horizon from your view point. The Willis Tower is ~1452 ft tall but Chicago has 580 ft elevation so the Willis Tower is ~2032 ft ASL, then you are seeing about 379.6 ft of the Top of the Willis Tower in that Photo ( a bit more considering the elevation of the Camera).